Plant pots of this type for commercial gardening are generally equipped with a bottom that contains openings for effective water drainage and also when water is supplied temporarily in excess, and on their undersides, with an interval from a placement surface for drainage of water and for ventilation. Surge-watering by means of spraying from above or so-called “ebb-and-flow watering,” in which the plant pots are flushed from time to time from below, first makes provision for water impingement that goes beyond a moisturizing requirement, that reduces drainage of excess water. To avoid waterlogging, especially a water drain on the bottom is to be provided if the plant pot stands on a placement surface that is wetted by water or even provided with water holes. Typically this is to be considered if the plant pots are placed on concrete floors, which form puddles on uneven ground when subjected to excess watering.
Since to save money and materials, plant pots in commercial gardening are designed with thin walls, and since the bottoms of such plant pots can sag downward due to filling, planting or root pressure, at least an inner section of the bottom of such plant pots are arched in cupola fashion. Outer sections of the bottom are stabilized by the adjoining wall, and also mostly made higher by protuberances like edge flanges or knubs. The upward archings are to be kept relatively flat, in order not to yield much pot space and not to create somewhat rugged edge areas in the pot. It is true that the result of this is that when the pot is vigorously filled with substrate and similar material, and also especially when tendril sticks and the like are inserted, the pot can be pressed or dented through in unwanted fashion. Thus, the plant pot no longer is capable of drainage and lacks strength.